It appears that you and I traveled the same online learning path to educate ourselves on gear oil. It's funny, how many of the same subjects, such as tranny oil, are discussed on other bike forums too. Rotella T has been my choice of oil for my 4-strokes. An 80 or 80W90 gear oil is my preference to ...

JPark, thanks for sharing the dimensions of your countershaft and sprocket! The 20x16x4 splines matches some of my 420 drive sprockets. dirty_rat, thanks for identifying the JT Sprockets that fit the different chain sizes used by Hodaka. I was only aware of the JTF546 because it matches my sprockets...

Thanks for your response JPark! I have Hodaka parts mixed in with other bike parts. I believe some of the sprockets I have fit the smaller Hodakas so that is why I was asking about the spline dimensions. I incorrectly asked for the spline crest width. The dimension I need is the width of the valley ...

I agree. Even if I found an API SH, SAE30 from Castrol, Mobil, etc., I don't think it would offer the protection of modern 75W/80 or straight weight 80 gear oils. If viscosity is a concern I am thinking the straight 80 might have a little higher viscosity than the 75W/80 since the tranny temp is bel...

Just offering information that I have collected over the years. Use at your own risk. I recall that one Hodaka manual I saw recommended SAE30. The minimum viscosity of SAE30 motor oil is 9.3 mm²/s at 100°C. The minimum viscosity of ATF is 5.6 mm²/s at 100°C. The minimum viscosity of Klotz Flex Drive...

Thanks for accepting me into Hodaka Club Forum! I am hoping that someone with calipers could provide me with the countershaft spline dimensions of a drive sprocket from a 90/100 cc bike. I need three dimensions of the splines; the maximum ID, the minimum ID and the spline crest width. I am also curi...